President Barack Obama and U.S. negotiators were outmaneuvered in the Iran nuclear proliferation accord, failing to deal from a position "of strength" – and needlessly leaving behind four American prisoners in Tehran, Donald Trump says.

In an interview set to air Sunday on WABC Radio in New York, the surging GOP presidential candidate derided Obama's assertion that the alternative to the nuclear deal was war. McClatchey posted audio of the interview on its website.

"This guy is too smart, and he's too sharp, and he's too cunning for [Secretary of State John] Kerry, and our bunch of negotiators," Trump says. "And that turned out to be totally right. … He’s their big hero right now, and that's because he beat us so badly at this."

Trump says "you would have thought" Obama "would have walked away. And yet, he folded, everything you could fold, and he just wants to get it done. It's incredible to me."

The deal itself, Trump says, is "just insulting, it’s such a bad deal… One of the really dumb deals I've ever seen."

"They did not read, 'The Art of The Deal,' that I can tell you," he said, referring to his how-to-do-business book. "Even a thing like the four prisoners that we don't get them out of it, and they say, 'We did want to complicate the negotiations.'

"How do you complicate the negotiations by asking for four people that should not be in jail? It is so disgraceful the way this was handled, and it shouldn’t have taken this time. They should have doubled up the sanctions. And I mean double and triple up the sanctions, and had them come home."

"I guarantee you if I was involved, they would have let ‘em out," he adds. "And, that's without the additional sanctions… They should have doubled up the sanctions, and negotiated from strength."

Trump decried that a "terrible deal" was forged even though "we had the cards."

"They don't have the cards – we have the cards," he declares, "Whether it's that deal, or trade deals, or Sgt. [Bowe] Bergdahl…."

Trump adds that Hillary Clinton's support of the Iran deal will hurt her in her campaign for the White House.

"Believe me if I'm chosen, I will be using this as one of many things against her, I can tell you that," he vowed.

Trump also blasts the period of waiting to check if there's any suspicions about undeclared nuclear materials or activities.

The agreement spells out that if the International Atomic Energy Agency and Iran can’t work out their differences over suspicions about undeclared nuclear materials or activities within 14 days, a joint commission empowered by the agreement would try to resolve the situation for another seven days. Once the commission decides what to do, Iran would have three more days to follow through.

"By that time, they'll clean everything up," he says. "You’ll go back, and say, 'oh, aren’t they wonderful people?' It has to be, 'Anywhere. Anytime!' Very simple."

President Barack Obama and U.S. negotiators were outmaneuvered in the Iran nuclear proliferation accord, failing to deal from a position "of strength" – and needlessly leaving behind four American prisoners in Tehran, Donald Trump says.